body {
    font: 14px "Microsoft Yahei", Arial;
}

#head {
    background: rgba(26, 26, 26, .9);
    width: 100%;
    height: 44px;
}

.wrapper {
    width: 1200px;
    margin: auto;
    position: relative;
}

.left {
    float: left;
    display: block;
}
.clear{
    overflow: hidden;
    :after{
        display: block;clear: both;content: ".";
        visibility: hidden;
        height: 0;
    }
}